Genetic variants linked to cancer

Scientists have identified two genetic risk factors linked to the most common form of breast cancer, paving the way for better early warning systems for those most at risk.

The genetic variants, following a DNA study of 100,000 women across the world, are specifically linked to the most common form of breast cancer, oestrogen receptor positive, and provide important insights into how the disease develops.

Scientists believe screening women for all the genetic variants so far identified could eventually pick out those at highest risk of breast cancer and improve strategies for preventing the disease.

The worldwide study was led by scientists at The Institute of Cancer Research, London. Around half of the participants had suffered with breast cancer.

Scientists said the study’s identification of two new genetic risk factors for breast cancer has provided important clues about the causes of the disease – implicating a gene called KLF4, which is thought to help control the way cells grow and divide.

The research involved scientists from more than 130 institutions worldwide, including the London School of Hygiene and Tropical Medicine, and the University of Cambridge.

Researchers were looking for one-letter differences in DNA code that were more likely to be found in women with breast cancer than those without the disease, using a state-of-the-art genetic technique called fine mapping.

Study leader Dr Nick Orr said: “Our study zoomed in on an area of our genome that we knew was linked to breast cancer risk, and has identified two new genetic variants that add significantly to our knowledge about the genetic causes of the disease.

“The variants we identified are specifically associated with the most common, oestrogen receptor positive, form of breast cancer.

“The more genetic risk factors for breast cancer we discover, of which there are currently more than 80, the more accurately we will be able predict who is at risk of getting the disease. Ultimately this will be vital for designing preventative strategies against breast cancer.”

She said: “Thanks to modern technology we’re building an increasingly detailed picture of the small variations in DNA that can influence a woman’s risk of breast cancer.

“The next challenges are understanding the biology underpinning their effects, so we can use this information to predict individual risk more accurately, improve screening and find better ways to treat and prevent breast cancer.”